Glycerol anhydrous

Figure 3 Comparison of the densities (in g/cm ) of model compounds for membrane lipids computed from constant-pressure MD simulations with the coiTespondmg experimental values. The model compounds include solid octane and tricosane, liquid butane, octane, tetradecane, and eico-sane, and the glycerylphosphorylcholme, cyclopentylphosphorylcholme monohydrate, dilauroly-glycerol, anhydrous cholesterol, cholesterol monohydrate, and cholesterol acetate crystals. (Models from Refs. 18, 42, and 43).

CijHgNj. Made by heating o-pheny-lenediamine with glycerol, nitrobenzene and cone, sulphuric acid. It exists as a monohydrate, m.p. 94" C, or anhydrous, m.p. 117°C. It is used as a complexing reagent in the estimation of Fe and in the preparation of numer-... 

When a mixture of anhydrous glycerol and crystalline oxalic acid, (C00H)2,2H lO, is heated the glycerol undergoes esterification, givang first glyceryl monoxalate (A) the latter, however, decomposes as the temperature... 

Required Aniline, 24 ml. nitrobenzene, 13 ml. anhydrous glycerol, 62 ml. sulphuric acid, 36 ml. zinc chloride, 23 g. 

Place 24 ml. (24 5 g.) of aniline, 13 ml. (15 5 g.) of nitro-benzene,t and 62 ml. (75 g.) of the anhydrous glycerol in the flask and mix thoroughly. (If the glycerol is still warm from the dehydration, cool the mixture in water.) Now add slowly 36 ml. (66 g.) of concentrated sulphuric acid, shaking the mixture thoroughly during the addition. The mixture at first... 

Use approximately 0 5 ml. of glycerol, and cork the flask A securely when weighing the glycerol by difference, owing to the very hygroscopic nature of the latter. Heat on the water-bath for 60 minutes instead of 30 minutes. Excellent results are obtained by this method if a freshly opened sample of anhydrous glycerol is available a sample which has been exposed to the air for even a short period will absorb sufficient water to give inaccurate results. 

Quinoline may be prepared by heating a mixture of aniline, anhydrous glycerol and concentrated sulphuric acid with an oxidising agent, such as nitrobenzene. The reaction with nitrobenzene alone may proceed with extreme violence, but by the addition of ferrous sulphate, which appears to function as an oxygen carrier, the reaction is extended over a longer period of time and Is under complete control. 

Properties. Antimony pentafluoride [7783-70-2], SbF, is a colorless, hygroscopic, very viscous liquid that fumes ia air. Its viscosity at 20°C is 460 mPa-s(=cP) which is very close to the value for glycerol. The polymerization of high purity SbF at ambient temperature can be prevented by addition of 1% anhydrous hydrogen fluoride, which can be removed by distillation prior to the use of SbF. The pure product melts at 7°C (11), boils at 142.7°C,... 

The preferred method of determining water in glycerol is by the Kad Fischer volumetric method (18). Water can also be determined by a special quantitative distillation in which the distilled water is absorbed by anhydrous magnesium perchlorate (19). Other tests such as ash, alkalinity or acidity, sodium chloride, and total organic residue are included in AOCS methods (13,16,18). 

The acid occurs both as colorless triclinic prisms (a-form) and as monoclinic prisms ( 3-form) (8). The P-form is triboluminescent and is stable up to 137°C the a-form is stable above this temperature. Both forms dissolve in water, alcohol, diethyl ether, glacial acetic acid, anhydrous glycerol, acetone, and various aqueous mixtures of the last two solvents. Succinic acid sublimes with partial dehydration to the anhydride when heated near its melting point. 

Physical Properties. Anhydrous sodium sulfite [7757-83-7] Na2S02, is an odorless, crystalline soHd and most commercial grades other than by-product materials are colorless or off-white (331—334). It melts only with decomposition. The specific gravity of the pure soHd is 2.633 (15.4°C). Sodium sulfite is quite soluble in water. It has a maximum solubiHty of 28 g/100 g sol at 33.4°C at higher and lower temperatures, it is less soluble in water. Below this temperature, the heptahydrate crystallizes above this temperature, the anhydrous salt crystallizes. Sodium sulfite is soluble in glycerol but insoluble in alcohol, acetone, and most other organic solvents. 

From Glycerol. A procedure for synthesizing alph a-m on ochl orohydrin (3-chloro-l,2-propanediol) in 85—88% yields by the reaction of glycerol [56-81-5] with aqueous hydrochloric acid in the presence of a catalytic amount of acetic acid has been developed (59). An anhydrous procedure that involves the reaction of glycerol and HCl gas in the presence of acetic acid has also been described (60). 

By heating glycerol with anhydrous magnesium sulfate. Evans and Hass, J. Am. Chcm. Soc. 48. 2703 (1926). 

Wang and coworkers first reported the use of these monomers as a novel elastomeric material for potential application in soft tissue engineering in 2002. The molar ratio of glycerol to sebacic acid they used was 1 1. The equimolar amounts of the two monomers were synthesized by polycondensation at 120°C for three days. The reaction scheme is shown in Scheme 8.1. To obtain the elastomers, they first synthesized a prepolymer and then poured an anhydrous 1,3-dioxolane solution of the prepolymer into a mold for curing and shaping under a high vacuum. 

Potassium bisulphate and anhydrous boric or oxalic acid are also used (acrolein from glycerol, pyruvic acid from tartaric acid). Tschugaev s xanthate method belongs to this class of reactions also. 

In order to obtain the glycerol quite pure and anhydrous the distillation must be repeated. 

The analogous chlorinated oxirane epichlorohydrin has also been prepared from glycerol. Glycerol is, therefore, first reacted with anhydrous HC1 to form di-chlorohydrins, which are further contacted with lime water to form epichlorohydrin (Scheme 11.19) [137-139]. 

The anhydrous salt consists of colorless rhombohedral crystals density 2.66 g/cm3 decomposes at 1,124°C dissolves in water (269 g/lOOmL at 0°C), ethanol and glycerol sparingly soluble in ether (1.16 g/mL at 18°C) insoluble in acetone. 

Epsom salt, or heptahydrate MgS02 7H2O, constitutes colorless monoclin-ic or rhombohedral crystals refractive index 1.433 density 1.68 g/cm loses six molecules of water of crystaUization at 150°C and converts to anhydrous form at 200°C highly soluble in water (71 g/lOOmL at 20°C) slightly soluble in alcohol and glycerol. 

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